EP0313648B1 - Verfahren zur stickstoffoxydminderung und zur minimierung der herstellung sonstiger schadstoffe - Google Patents

Verfahren zur stickstoffoxydminderung und zur minimierung der herstellung sonstiger schadstoffe Download PDF

Info

Publication number
EP0313648B1
EP0313648B1 EP88905072A EP88905072A EP0313648B1 EP 0313648 B1 EP0313648 B1 EP 0313648B1 EP 88905072 A EP88905072 A EP 88905072A EP 88905072 A EP88905072 A EP 88905072A EP 0313648 B1 EP0313648 B1 EP 0313648B1
Authority
EP
European Patent Office
Prior art keywords
effluent
nitrogen oxides
treatment regimen
treatment agent
treatment
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP88905072A
Other languages
English (en)
French (fr)
Other versions
EP0313648A4 (de
EP0313648A1 (de
Inventor
William Robert Epperly
John Henry O'leary
James Christopher Sullivan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fuel Tech Inc
Original Assignee
Fuel Tech Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=21963912&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0313648(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Fuel Tech Inc filed Critical Fuel Tech Inc
Publication of EP0313648A1 publication Critical patent/EP0313648A1/de
Publication of EP0313648A4 publication Critical patent/EP0313648A4/de
Application granted granted Critical
Publication of EP0313648B1 publication Critical patent/EP0313648B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/54—Nitrogen compounds
    • B01D53/56—Nitrogen oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00049—Controlling or regulating processes
    • B01J2219/00051—Controlling the temperature
    • B01J2219/00054—Controlling or regulating the heat exchange system
    • B01J2219/00056—Controlling or regulating the heat exchange system involving measured parameters
    • B01J2219/00058—Temperature measurement
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/30—Wastewater or sewage treatment systems using renewable energies
    • Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy

Definitions

  • the present invention relates to a non-catalytic process for the reduction of nitrogen oxides (NO x ) in the effluent, especially the oxygen-rich effluent, from the combustion of a carbonaceous fuel while minimizing the production of ammonia (NH3) and carbon monoxide (CO).
  • NO x nitrogen oxides
  • NH3 ammonia
  • CO carbon monoxide
  • Carbonaceous fuels can be made to burn more completely, and with reduced emissions of carbon monoxide and unburned hydrocarbons, when the oxygen concentrations and air/fuel ratios employed are those which permit high flame temperatures.
  • temperatures above about 1093°C (2000°F) and typically about 1204°C (2200°F) to about 1649°C (3000°F) are generated.
  • thermal NO x the temperatures being so high that free radicals of oxygen and nitrogen are formed and chemically combine as nitrogen oxides.
  • Nitrogen oxides can form even in circulating fluidized bed boilers which operate at temperatures which typically range from 704°C (1300°F) to 927°C (1700°F).
  • Nitrogen oxides are troublesome pollutants which are found in the combustion effluent streams of boilers when fired as described above, and comprise a major irritant in smog. It is further believed that nitrogen oxides can undergo a process known as photo-chemical smog formation, through a series of reactions in the presence of sunlight and hydrocarbons. Moreover, nitrogen oxides comprise a significant contributor to acid rain.
  • EP-A-306 515 corresponding to a U.S. priority application filed in the names of Epperly, Peter-Hoblyn, Shulof and Sullivan entitled "Multi-Stage Process for Reducing the Concentration of Pollutants in an Effluent" having Serial Number 022,716, filed March 6, 1987, disclose a method of achieving substantial NO x reductions without the production of a major amount of other pollutants through a multiple stage injection process.
  • the present invention meets this need and provides the ability to control NO x in concert with other pollutants in an effluent from the combustion of a carbonaceous fuel under varying as well as constant load conditions in a manner and to a degree never before available.
  • the process comprises
  • an object of the present invention is to achieve significant reductions in nitrogen oxides levels without the production of substantial amounts of ammonia and carbon monoxide by effecting a treatment regimen while monitoring the condition of the effluent and, when a change in effluent condition is observed, adjusting the treatment regimen by varying one or more of the above-mentioned treatment regimen parameters to effect an adjusted treatment regimen which operates on its nitrogen oxides reduction versus effluent temperature curve further to the right than did the originally- effected treatment regimen on its nitrogen oxides reduction versus effluent temperature curve.
  • Another object according to the present invention is to achieve significant reductions in nitrogen oxides levels without the production of substantial amounts of ammonia and carbon monoxide by determining the nitrogen oxides reduction versus effluent temperature curves for each of a plurality of treatment regimen and effecting the treatment regimen which will, under the effluent condition currently existing, operate furthest to the right on its curve than the others.
  • Still another object according to the present invention is to achieve significant reductions in nitrogen oxides levels without the production of substantial amount of ammonia and carbon monoxide by effecting a treatment regimen and adjusting the position of introduction of the treatment regimen to cause the introduction to be performed at a different effluent temperature and thereby effect the treatment regimen to operate more towards the right side of the plateau of its nitrogen oxides reduction versus effluent temperature curve.
  • Yet another object according to the present invention is to achieve significant reductions in nitrogen oxides levels without the production of substantial amounts of ammonia and carbon monoxide by effecting a treatment regimen under conditions effective to reduce the effluent nitrogen oxides concentration and then varying one or more of the above-mentioned treatment regimen parameters to shift the treatment regimen nitrogen oxides reduction versus effluent temperature curve further towards the right side of the curve plateau.
  • Still another object according to the present invention is to achieve significant reductions in nitrogen oxides levels without the production of substantial amounts of ammonia and carbon monoxide by effecting a treatment regimen, determining the position on its nitrogen oxides reduction versus effluent temperature curve at which the treatment regimen is operating and varying one or more of the above-mentioned treatment regimen parameters so that the varied treatment regimen is operating on its nitrogen oxides reduction versus effluent temperature curve further to the right.
  • Another object according to the present invention is to achieve significant reductions in nitrogen oxides levels without the production of substantial amounts of ammonia and carbon monoxide by effecting a treatment regimen and varying one or more of the foregoing regimen parameters to drive the reaction or series of reactions by which the treatment regimen reduces nitrogen oxides towards a reduction of the production of ammonia and carbon monoxide while substantially maintaining the level of nitrogen oxides reductions.
  • Yet another object according to the present invention is to achieve significant reductions in nitrogen oxides levels without the production of substantial amounts of ammonia and carbon monoxide by effecting a treatment regimen while monitoring boiler operating load and varying one or more of the foregoing treatment regimen parameters when a significant change in boiler load is observed to effect an adjusted treatment regimen.
  • Another object according to the present invention is to achieve significant reductions in nitrogen oxides levels without the production of substantial amounts of ammonia and carbon monoxide by effecting a treatment regimen under conditions where the treatment regimen is operating on its nitrogen oxides reduction versus effluent temperature curve at a position to the right of the curve plateau and adjusting one or more of the aforementioned treatment regimen parameters to operate the adjusted treatment regimen towards its curve plateau.
  • Still another object according to the present invention is to ascertain the condition of the effluent by effecting a treatment regimen, measuring the condition of the effluent and, by reference to the nitrogen oxides reduction versus effluent temperature curve, determine what the condition of the effluent was prior to the treatment regimen being effected.
  • nitrogen oxides reduction versus effluent temperature curve refers to a plot of the data points generated when a treatment regimen is effected by introducing a treatment agent into an effluent over a range of effluent temperatures and the nitrogen oxides reduction at each introduction temperature is measured (and usually expressed in terms of percent of baseline);
  • curve plateau refers to that region of a nitrogen oxides reduction versus effluent temperature curve where the NO x reduction is substantially maximized over a range of temperatures and preferably encompasses at least two data points (of course a skilled artisan will recognize that a curve plateau will not necessarily be flat due to "data scatter” and other practical data generation effects);
  • “high temperature side” or “right side” refer to any point on the subject nitrogen oxides reduction versus effluent temperature curve which represents the reduction achieved when a treatment regimen is effected at a higher temperature than the original temperature at which a treatment regimen was effected;
  • treatment regimen refers to the introduction (such as by injection) of
  • Appropriate treatment agents known as being effective at the reduction of nitrogen oxides include aqueous solutions of urea or ammonia, or gaseous ammonia, as disclosed in EP-A-238 654 (which corresponds to a U.S. Patent Application entitled “Reduction of Nitrogen- and Carbon-Based Pollutants Through the Use of Urea Solutions” having Serial No. 784,826, filed in the name of Bowers on October 4, 1985); EP-A-242 394 (which corresponds to a U.S. Patent Application entitled “Reduction of Nitrogen Based Pollutants Through the Use of Urea Solutions Containing Oxygenated Hydrocarbon Solvents" having Serial No. 784,828, filed in the name of Bowers on October 4, 1985); and US-A-3,900,554.
  • treatment agents which comprise other compositions such as hexamethylenetetramine (HMTA), ethylene glycol, furfural, hydrocarbons, sugar, milk or skimmed milk, amino acids, proteins and monoethanolamine are disclosed as being effective at the reduction of nitrogen oxides in an effluent in combination with aqueous solutions of urea or ammonia in several disclosures.
  • HMTA hexamethylenetetramine
  • EP-A-237 568 which corresponds to a U.S. Patent Application entitled “Reduction of Nitrogen-and Carbon-Based Pollutants” having Serial No. 906,671, filed in the name of Bowers on September 6, 1986.
  • Other disclosures which teach the use of such compositions include EP-A-301 085 (which corresponds to a U.S. Patent Application entitled “Process for the Reduction of Nitrogen Oxides in an Effluent” having Serial No. 014,431, filed in the names of Epperly and Sullivan on February 13, 1987); EP-A-305 503 (which corresponds to a U.S.
  • the nitrogen oxides reduction versus effluent temperature curve for a treatment regimen comprises a curve plateau, which, as described above, indicates where the NO x reduction elicited by the treatment regimen is maximized and that such maximum level is substantially maintained over a range of effluent temperatures.
  • An exemplary nitrogen oxides reduction versus effluent temperature curve for a treatment regimen disclosed as being an effective nitrogen oxides reducing treatment regimen is reproduced as Figure 1.
  • Figure 1 is the nitrogen oxides reduction versus effluent temperature curve for a treatment regimen comprising a treatment agent which comprises 10% by weight of urea, 4% by weight of hexamethylenetetramine and 10% by weight of furfural, which is injected into an effluent at the rate of 300 ml/hr. and an excess of oxygen in the effluent of 3.0% by volume.
  • a treatment agent which comprises 10% by weight of urea, 4% by weight of hexamethylenetetramine and 10% by weight of furfural, which is injected into an effluent at the rate of 300 ml/hr. and an excess of oxygen in the effluent of 3.0% by volume.
  • the curve plateau for Figure 1 will be recognized as the nitrogen oxides reduction achieved by effecting the disclosed treatment regimen between effluent temperatures of 832°C (1530°F) and 916°C (1680°F) (the skilled artisan will recognize that due to normal experimental variations, the curve plateau, and indeed the nitrogen oxides reduction versus effluent temperature curve itself, for any given treatment regimen will show minor variations each time it is experimentally derived). This temperature range, it will be observed, provides the maximum nitrogen oxides reduction for this treatment regimen.
  • nitrogen oxides reduction Merely maximizing the nitrogen oxides reduction, though, is not enough. Of concern is not only the nitrogen oxides level in the effluent, but also the level of other pollutants, such as ammonia and carbon monoxide which are often produced in the NO x reducing process. For instance, when NO x reduction is achieved by using treatment agent comprising urea alone, ammonia is produced, whereas when NO x reduction is achieved by use of a treatment agent comprising urea enhanced with a disclosed enhancer, or by use of a hydrocarbon treatment agent, ammonia and carbon monoxide are produced.
  • ammonia in the effluent should be avoided because, among other reasons, it can react with SO3 to form ammonium bisulfate which can foul heat exchange surfaces in a boiler. If the maximization of the nitrogen oxides level brings about the production of significant amounts of other pollutants, then such maximization is counterproductive. As discussed above, the prior art has attempted to rectify this by eliciting only that level of nitrogen oxides reduction as can be achieved without the production of other pollutants.
  • Figure 1 reproduces the nitrogen oxides reduction versus effluent temperature curve for a treatment regimen which is effective at reducing the nitrogen oxides level in an effluent from the combustion of a carbonaceous fuel.
  • Figure 1a reproduces that same nitrogen oxides reduction versus effluent temperature curve and further has superimposed thereon the ammonia and carbon monoxide levels observed a each point on the curve. It can be seen that although NO x reduction is maximized throughout the curve plateau (i.e., injection in the effluent temperature range of about 1530°F. to about 1680°F.), performing the injection further to the right on the curve plateau (i.e., at higher temperatures in the plateau temperature range) leads to substantially reduced production of ammonia and carbon monoxide.
  • Operation further to the right on the curve can be achieved in one of two methods.
  • First, the position on the curve at which the treatment regimen being used is being effected can be translated further to the right by effecting the treatment regimen at a higher effluent temperature. It will readily be observed by reference to Figures 1 and 1a that effecting the treatment regimen at a higher effluent temperature will translate the position of operation on the curve further to the right, thereby reducing the production of ammonia and carbon monoxide while maintaining maximum nitrogen oxides reduction.
  • Effecting the treatment regimen at a higher effluent temperature can be accomplished by performing the treatment agent introduction at a location where the effluent temperature is higher, i.e., at a location upstream (or closer to the flame zone) from the original introduction location.
  • This method for effecting the treatment regimen at a higher effluent temperature can oftimes be impractical because access to the boiler interior is often limited to specific points, due to water tubing, etc. Introduction at a location where the effluent temperature is at a desired level, therefore, is often not possible. Operation at a much higher effluent temperature can translate the position of operation on the curve too far to the right and off the plateau, thereby decreasing NO x reduction.
  • Altering the operating load of the boiler i.e., fuel supply rate
  • altering the boiler operating load is not preferred because the effluent condition is altered in more than the temperature parameter, as will be discussed in more detail below.
  • Nitrogen oxides level, as well as other parameters such as ammonia level and carbon monoxide level are altered along with effluent temperature.
  • the boiler operating load is usually maintained at a certain level to produce a specific, required output and is not available as a factor which can be altered to achieve NO x reduction.
  • the second method for operating further to the right on the curve is to vary one or more of the parameters of the treatment regimen being effected.
  • the varied parameter can be the components of the treatment agent, the dilution of the treatment agent when in solution with a concommitant variation in treatment agent introduction rate to maintain the NSR of the treatment regimen (as discussed above, the NSR refers also to the molar ratio of the treatment agent to the baseline nitrogen oxides level, where appropriate), the relative presence of treatment agent components, or combinations of any of the above.
  • the original nitrogen oxides reduction versus effluent temperature curve is replaced by the nitrogen oxides reduction versus effluent temperature curve for the varied treatment regimen. Selection of the parameter(s) to be varied and in what way they are varied can replace the original curve with a curve which is "shifted" to the left, thereby leading to operation on the shifted curve at a position further to the right.
  • FIG. 2 provides the nitrogen oxides reduction versus effluent temperature curve plateau for three treatment regimens which each comprise introducing a treatment agent into an effluent over a range of effluent temperatures and at an introduction rate of 300 ml/hr. and an excess of oxygen of 3.0% by volume.
  • the treatment agent introduced for the first treatment regimen comprises an agueous solution of 10% urea and 15% furfural;
  • the treatment agent introduced for the second treatment regimen comprises an aqueous solution of 10% urea;
  • the treatment agent introduced for the third treatment regimen comprises an aqueous solution of 10% urea and 15% ethylene glycol.
  • the treatment regimen being effected comprises a treatment agent which is an aqueous solution of 10% urea
  • the effluent temperature at the treatment location is 957°C (1755°F)
  • varying the treatment regimen by varying the treatment agent components by injecting 15% furfural with the 10% urea replaces the original curve with a curve at which introduction at that effluent temperature operates further towards the right side of the curve plateau.
  • the treatment regimen being effected comprises a treatment agent which is an aqueous solution of 10% urea and 15% furfural, and the effluent temperature at the point of introduction is 907°C (1665°F), thereby operating near the midpoint of the treatment regimen nitrogen oxides reduction versus effluent temperature curve plateau, then varying the treatment regimen to vary the treatment agent to replace the 15% furfural with 15% ethylene glycol replaces the original curve with a curve at which introduction at that effluent temperature operates further towards the right side of the curve plateau.
  • the two methods for operating further to the right on the curve plateau disclosed according to the present invention are not mutually exclusive, but can in fact be combined.
  • the effluent temperature can be varied along with one or more treatment regimen parameters.
  • varying one or more treatment regimen parameters serves to produce an adjusted (or new) treatment regimen which will have a different (or shifted) nitrogen oxides reduction versus effluent temperature curve compared to the original treatment regimen.
  • the nitrogen oxides reduction versus effluent temperature curve for a plurality of treatment regimens such as aqueous solutions comprising 10% by weight of urea and varying amounts of ethylene glycol which are introduced into an effluent over a range of effluent temperatures and at an introduction rate of 300 ml/hr and an excess of oxygen of 3.0% by volume, can be plotted.
  • the data which comprises the plots can then be compared to determine which treatment regimen should be effected according to this invention for the effluent condition existing at the injection location.
  • the desired treatment regimen is the regimen which comprises the treatment agent having 10% ethylene glycol, as illustrated in Figure 3e (the 15% ethylene glycol treatment regimen is not desired at 899°C (1650°F) because, although Figure 3e indicates ammonia and carbon monoxide levels are low, NO x reduction is also lower than the maximum, indicating that the 15% ethylene glycol treatment regimen is operating on its nitrogen oxides reduction versus effluent temperature curve to the right and off the curve plateau).
  • the desired treatment regimen is the regimen which comprises the treatment agent having 5% ethylene glycol, as illustrated in Figure 3f, because both the 10% ethylene glycol and 15% ethylene glycol treatment regimens are operating to the right and off their curve plateau.
  • Another advantageous aspect of the present invention is in the situation where an effluent from the combustion of a carbonaceous fuel is required to have no more than a maximum level of ammonia and/or carbon monoxide.
  • the process of this invention can be used to achieve the maximum possible NO x reduction, or a target level of NO x reduction, while maintaining the level of such other pollutants under such maximum level.
  • NSR normalized stoichiometric ratio
  • the NSR is increased until the first of such other pollutants reaches its maximum level. In this way, the highest possible NO x reduction can be achieved while maintaining the effluent in a condition which is below the maximum level for other pollutants.
  • a treatment regimen which comprises an aqueous solution of 10% urea and 15% ethylene glycol introduced into an effluent at an introduction rate of 300 ml/hr. and an excess of oxygen of 3.0% has a nitrogen oxides reauction versus effluent temperature curve which is graphically reproduced as Figure 3c, which graphically reproduces the results of Example IIIc. It will be observed by reference to Figure 3c that this treatment regimen is operating towards the left side of its curve at an effluent temperature of 846°C (1555°F), in the midsection of its curve at an effluent temperature of 885°C (1625°F), and towards the right side of its curve at an effluent temperature of 957°C (1755°F).
  • the NSR can be increased until the nitrogen oxides reduction is sufficient to attain that level of nitrogen oxides, provided that a maximum level of the other pollutants is not surpassed. In this way, if the treatment regimen is operating on the right side of its curve plateau, the target level of NO x is attained while a minimum of the other pollutants are produced.
  • the process of this invention can be used to reduce NO x levels while minimizing the production of other pollutants through "load following.”
  • Load following refers to a process which involves adjusting the treatment regimen which is being effected in response to the operating load at which the boiler is being fired. When the boiler operating load changes, a change in effluent temperature occurs. Such a change in temperature of the effluent, it will be apparent, causes the point of operation on the nitrogen oxides reduction versus effluent temperature curve for the current treatment regimen to be translated either to the left, and hence away from minimization of other pollutants, or to the right, potentially off the curve plateau and onto the right side slope of the curve, and hence away from maximum nitrogen oxides reduction.
  • the nitrogen oxides reduction versus effluent temperature curve is shifted (i.e., replaced with a new nitrogen oxides reduction versus effluent temperature curve) so that operation after the change is once again towards the right side of the curve plateau.
  • a change in boiler operating load leads to more than merely a change in effluent temperature.
  • a change in boiler load produces a change in the effluent with regard to NO x level. This becomes especially important when there is a maximum level of the other pollutants which has to be met or a target level of nitrogen oxides reduction which has to be attained.
  • the change in NO x level can be measured directly or, preferably, can be determined using a load-dependent boiler characterization factor.
  • the characterization factor relates the NO x level and temperature of the effluent at given locations to boiler load, and it is determined experimentally.
  • the treatment regimen being effected at a given location can be adjusted immediately upon change of boiler operating load as measured by fuel supply rate, for example.
  • the treatment regimen feed rate is reduced to achieve the NSR needed to attain target reductions at that load and the treatment agent components are varied as necessary to respond to the temperature change resulting from the change in operating load. If the feed rate of the treatment regimen were not reduced, the NSR would be excessive in view of the lower level of NO x and excessive NH3 and CO would be produced.
  • This characterization factor is dependent on boiler geometry, fuel type and boiler load and can be determined experimentally. Several other parameters such as number of burners in service affect the characterization factor, but those that are mentioned above are most important.
  • the nitrogen oxides level and temperature at a given location can be determined to a sufficient degree of certainty to permit the determination of how the treatment regimen should be adjusted to correct for translation on the nitrogen oxides reduction versus effluent temperature curve which occurs when the operating load is changed and for the change in NSR.
  • the preferred embodiment for maximizing nitrogen oxides reduction and controlling the production of other pollutants is by effecting a first treatment regimen which operates at the effluent temperatures currently existing on the right hand slope, off the curve plateau, of the treatment regimen's nitrogen oxides reduction versus effluent temperature curve.
  • a first treatment regimen which operates at the effluent temperatures currently existing on the right hand slope, off the curve plateau, of the treatment regimen's nitrogen oxides reduction versus effluent temperature curve.
  • Another surprising aspect of this invention is in the use of a treatment regimen as a probe for effluent conditions. If the nitrogen oxides reduction versus effluent temperature curve (or, in fact, the ammonia or carbon monoxide production versus effluent temperature curves) for a treatment regimen is known, the effluent condition after that treatment regimen is effected will provide useful information about the effluent condition downstream from the location the treatment regimen is effected, it can even provide information on boiler operating load. For instance, if the nitrogen oxides level is relatively low, but the level of production of other pollutants is relatively high, then it can be assumed that the treatment regimen is operating on the left side of its curve plateau.
  • the effluent temperature can be determined with a reasonable degree of accuracy and, using the boiler characterization factor described above, the boiler load can be determined. Similarly, if the NO x , ammonia and carbon monoxide levels are all low, it can be assumed that the treatment regimen is operating on the right side slope, off the curve plateau, of its curve. Effluent temperature and boiler operating load can then be determined therefrom. The more intimate familiarity with the treatment regimen's curve, the more accurate the determinations can be.
  • the burner used is a burner having an effluent flue conduit, known as a combustion tunnel, approximately 209 inches in length and having an internal diameter of 8 inches and walls 2 inches thick.
  • the burner has a flame area adjacent the effluent entry port and flue gas monitors adjacent the effluent exit port to measure the concentration of compositions such as nitrogen oxides, sulfur oxides, ammonia, carbon monoxide, carbon dioxide, percent excess oxygen and other compounds of interest which may be present in the effluent.
  • the effluent flue conduit additionally has thermocouple ports for temperature measurement at various locations. The temperature of the effluent into which the treatment agents are injected is measured at the location of injection utilizing a K-type thermocouple.
  • Atomizing injectors described in EP-A-300 028 which corresponds to a U.S. Patent Application entitled "Process an Apparatus for Reducing the Concentration of Pollutants in an Effluent" having Serial Number 009,696, filed in the name of Burton on February 2, 1987 are positioned through ports in the effluent flue conduit in order to introduce and distribute the treatment agents into the effluent stream.
  • the agents are injected into the effluent at a rate of 300 ml/hr.
  • the burner fuel is a Number 2 fuel oil, and the burner is fired at a rate of 4.4 kgs/hr (9.6 lbs/hr) with an excess of oxygen of 3.0% by volume.
  • a baseline nitrogen oxides concentration reading is taken prior to beginning each run to calculate the injection ratio of treatment agent to baseline nitrogen oxides and the NSR, and a final nitrogen oxides reading is taken during and downstream from injection of the treatment agents to calculate the reduction in the nitrogen oxides concentration in the effluent elicited by each of the treatment agents injected. Moreover, an ammonia and carbon monoxide reading is taken during and downstream from injection of the treatment agents to calculate the production of other pollutants.
  • Aqueous solutions comprising 10% by weight of urea, 4% by weight of hexamethylenetetramine, 10% by weight of furfural and 0.1% by weight of a commercially available surfactant are injected into the effluent at the indicated temperatures.
  • Table 1 Temp.°C (°F.) NO x (ppm) Baseline NO x (ppm) Final % Red.
  • Example II The procedure followed is that of Example I except that the boiler is fired at a rate of 4.4 kgs/hr to 5.44 kgs/hr (9.6 lbs/hr to 12.0 lbs/hr) to acheive the effluent temperatures.
  • the treatment agent injected is an aqueous solution which comprises 10% by weight of urea, 15% by weight of furfural, and 0.1% by weight of a commercially available surfactant.
  • the injection temperature, % excess oxygen, NSR, baseline NO x , final NO x and % reduction of NO x for each run is set out in Table 2a and reproduced graphically in Figure 2.
  • Example IIa The procedure of Example IIa is repeated except that the treatment agent which is injected is an aqueous solution comprising 10% by weight of urea and 0.1% by weight of a commercially available surfactant.
  • the results are set out in Table 2b and reproduced graphically in Figure 2.
  • Table 2b Run Temp. °C (°F.) O2% NSR NO x (ppm) % Red.
  • Example IIa The procedure of Example IIa is repeated except that the treatment agent injected is an aqueous solution comprising 10% by weight of urea, 15% by weight of ethylene glycol and 0.1% by weight of a commercially available surfactant.
  • the results are set out in Table 2c and reproduced graphically in Figure 2.
  • Table 2c Run Temp. °C (°F.) O2% NSR NO x (ppm) % Red.
  • Example II The procedure of Example I is followed except that the boiler is fired at a rate of 4.4 kgs/hr to 49.0 kgs/hr (9.6 lbs/hr. to 10.8 lbs/hr).
  • the treatment agent injected comprises an aqueous solutions of 10% by weight of urea, 5% by weight of ethylene glycol and 0.1% by weight of a commercially available surfactant.
  • Table 3a Temp. °C (°F.) NO x (ppm) Baseline NO x (ppm) Final % Red.
  • Example IIIa The procedure of Example IIIa is followed except that the treatment agent injected comprises an aqueous solution of 10% by weight of urea, 10% by weight of ethylene glycol and 0.1% by weight of a commercially available surfactant.
  • the results are set out in Table 3b and reproduced graphically in Figure 3b.
  • Table 3b Temp. °C (°F.) NO x (ppm) Baseline NO x (ppm) Final % Red.
  • Example IIIb The procedure of Example IIIb is followed except that the treatment agent injected comprises an aqueous solution of 10% by weight of urea, 15% by weight of ethylene glycol and 0.1% by weight of a commercially available surfactant.
  • the results are set out in Table 3c and graphically reproduced in Figure 3c.
  • Table 3c Temp. °C (°F.) NO x (ppm) Baseline NO x (ppm) Final % Red.
  • a treatment agent comprising an aqueous solution of 10% by weight of urea, 15% by weight of ethylene glycol and 0.1% by weight of a commercially available surfactant is injected into the effluent combustion tunnel described in Example I at a range of NSRs and the production of ammonia measured.
  • the normalized stoichiometric ratio (NSR) for each injection and the results are set out in Table 4 and graphically reproduced in Figure 4.
  • NSR normalized stoichiometric ratio

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Health & Medical Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Treating Waste Gases (AREA)
  • Catalysts (AREA)
  • Separation By Low-Temperature Treatments (AREA)
  • Control Of Turbines (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
  • Solid Fuels And Fuel-Associated Substances (AREA)

Claims (13)

  1. Nicht-katalytisches Verfahren zur Verminderung der Konzentration von Stickstoffoxiden in einem Abgas aus der Verbrennung eines kohlenstoffhaltigen Brennstoffs unter Minimierung der Bildung von Ammoniak und Kohlenmonoxid, wobei das Verfahren umfaßt:
    (a) die Durchführung eines Behandlungskonzepts, umfassend die Einleitung einer wäßrigen Lösung eines Harnstoff umfassenden chemischen Behandlungsmittels in das Abgas;
    (b) Überwachen des Zustands des Abgases, bis eine Änderung im Zustand des Abgases beobachtet wird; und
    (c) Anpassen des Behandlungskonzepts durch Variieren von mindestens einem der folgenden Parameter
    i. Verdünnung des Behandlungsmittels,
    ii. Bestandteile des Behandlungsmittels,
    iii. relativ enthaltene Mengen an Behandlungsmittelbestandteilen, und
    iv. Ort, an dem die Einleitung des Behandlungsmittels erfolgt,
    zur Durchführung eines angepaßten Behandlungskonzepts, das eine aus dem Auftragen von Werten für die Verminderung an Stickstoffoxiden gegen Temperaturwerte sich ergebende Kurve aufweist, die ein Kurvenplateau, umfaßt,
    wobei das angepaßte Behandlungskonzept auf der rechten Seite des Kurvenplateaus der Verminderung der Stickstoffoxide gegen die Temperatur wirkt.
  2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Behandlungskonzept im Schritt (a) und, falls erforderlich, die Anpassung des Behandlungskonzepts im Schritt (c) unter Durchführen einer Mehrzahl von Behandlungskonzepten durchgeführt werden, umfassend:
    (a) die Bestimmung durch Messung oder Berechnung der sich aus der Verminderung der Stickstoffoxide gegen die Abgastemperatur ergebenden Kurve für jedes einer Mehrzahl von Behandlungskonzepten,
    (b) Feststellen durch Vergleich, welches Behandlungskonzept, wenn es zur Behandlung eines Abgases mit der an einem Ort für das Einspritzen bestehenden Abgastemperatur durchgeführt wird, an einem auf seinem Kurvenplateau am weitesten rechts gelegenen Punkt wirkt, und
    (c) Durchführen des festgestellten Behandlungskonzepts zur Verminderung der Konzentration der Stickstoffoxide im Abgas, wobei die Bildung von Ammoniak und Kohlendioxid im wesentlichen vermieden wird.
  3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Behandlungskonzept im Schritt (a) und, falls erforderlich, die Anpassung des Behandlungskonzepts im Schritt (c) bewirkt werden durch Einleiten einer wäßrigen Lösung eines chemischen Behandlungsmittels mit einer bekannten, sich aus der Verminderung der Stickstoffoxide gegen die Abgastemperatur ergebenden und ein Kurvenplateau aufweisenden Kurve in das Abgas zur Verminderung der Konzentration von Stickstoffoxiden im Abgas durch eine Reaktion oder Serie von Reaktionen, die durch das Behandlungsmittel erleichtert werden, und durch Einstellen der Einspritzstelle, wodurch bewirkt wird, daß die Einspritzung bei einer unterschiedlichen Abgastemperatur durchgeführt wird, wobei die Reaktion oder Serie von Reaktionen zur rechten Seite des Plate- aus der sich aus der Verminderung der Stickstoffoxide gegen die Abgastemperatur ergebenden Kurve verschoben wird.
  4. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Behandlungskonzept im Schritt (a) unter
    (a) Einleiten einer wäßrigen Lösung eines chemischen Behandlungsmittels in das Abgas zur Verminderung der Konzentration der Stickstoffoxide im Abgas durch eine Reaktion oder eine Serie von Reaktionen, die durch das Behandlungsmittel erleichtert werden, und
    (b) Variieren von mindestens einem der folgenden Parameter
    i. Verdünnung des Behandlungsmittels,
    ii. Bestandteile des Behandlungsmittels
    iii. Verhältnis der Bestandteile des Behandlungsmittels, und
    iv. Einspritzort
    durchgeführt wird, um die Reaktion oder Serie von Reaktionen in Richtung der Verminderung der Bildung von Ammoniak und Kohlenmonoxid zu verschieben, während das Ausmaß der Verminderung an Stickstoffoxiden im wesentlichen aufrechterhalten wird.
  5. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Behandlungskonzept im Schritt (a) und, falls erforderlich, die Einstellung des Behandlungskonzepts im Schritt (c) wie folgt durchgeführt werden
    (a) Durchführen eines ersten Behandlungskonzepts, umfassend die Einleitung einer wäßrigen Lösung eines chemischen Behandlungsmittels in das Abgas zur Behandlung des Abgases zur Verminderung der Konzentration der Stickstoffoxide im Abgas durch eine Reaktion oder eine Serie von Reaktionen, die durch das erste Behandlungskonzept erleichtert werden,
    (b) Bestimmen der Stelle auf der sich aus der Verminderung der Stickstoffoxide gegen die Abgastemperatur ergebenden Kurve für das Behandlungsmittel, bei der das erste Behandlungskonzept durchgeführt wird,
    (c) Einstellen des ersten Behandlungskonzepts durch Variieren von mindestens einem der folgenden Parameter
    i. Verdünnung des Behandlungsmittels,
    ii. Bestandteile des Behandlungsmittels, und
    iii. Verhältnis der Bestandteile des Behandlungsmittels um ein zweites Behandlungskonzept durchzuführen, und
    (d) Bestimmen der Stelle auf der sich aus der Verminderung der Stickstoffoxide gegen die Abgastemperatur ergebenden Kurve für das zweite Behandlungskonzept, bei der das zweite Behandlungskonzept durchgeführt wird,
    wobei die Stelle, bei der das zweite Behandlungskonzept durchgeführt wird, sich weiter rechts auf der sich aus der Verminderung der Stickstoffoxide gegen die Abgastemperatur ergebenden Kurve befindet, als die Stelle, bei der das erste Behandlungskonzept auf der sich aus der Verminderung der Stickstoffoxide gegen die Abgastemperatur ergebenden Kurve durchgeführt wird.
  6. Verfahren nach einem der Ansprüche 1 bis 5, wobei der überwachte Zustand des Abgases ausgewählt wird aus der Gruppe Betriebslast des Kessels, Abgastemperatur an der Stelle der Einleitung eines Behandlungsmittels, Menge der Stickstoffoxide im Abgas, Menge an Ammoniak im Abgas, Menge an Kohlenmonoxid im Abgas, Menge an überschüssigem Sauerstoff im Abgas, und Kombinationen davon.
  7. Verfahren nach Anspruch 6, wobei der überwachte Abgaszustand die Abgastemperatur ist.
  8. Verfahren nach Anspruch 1, wobei der überwachte Abgaszustand die Betriebslast des Kessels ist.
  9. Verfahren nach einem der Ansprüche 1 bis 8, das zusätzlich die Erhöhung der Einleitungsgeschwindigkeit des Behandlungsmittels zur Erhöhung des normalisierten stöchiometrischen Verhältnisses umfaßt, bis ein vorbestimmtes Höchstmaß an anderen Schadstoffen im wesentlichen erreicht aber nicht überschritten wird.
  10. Verfahren nach einem der Ansprüche 1 bis 9, das zusätzlich die Erhöhung der Einleitungsgeschwindigkeit des Behandlungsmittels zur Erhöhung des normalisierten stöchiometrischen Verhältnisses umfaßt, bis ein vorbestimmter Sollwert an Verminderung von Stickstoffoxiden erreicht wird, mit der Maßgabe, daß ein vorbestimmtes Höchstmaß an anderen Schadstoffen nicht überschritten wird.
  11. Verfahren nach einem der Ansprüche 1 bis 10, wobei das Behandlungsmittel zusätzlich einen oder mehrere Kohlenwasserstoffe umfaßt.
  12. Verfahren nach Anspruch 11, wobei der Kohlenwasserstoff ausgewählt ist aus Stickstoff enthaltenden Kohlenwasserstoffen, oxidierten Kohlenwasserstoffen, Hydroxyaminokohlenwasserstoffen, heterocyclischen Kohlenwasserstoffen und Gemischen davon.
  13. Verfahren nach einem der Ansprüche 1 bis 12, wobei das Behandlungsmittel weiter einen Verstärker umfaßt, ausgewählt aus Furfural, Zucker, Milch, Glycin, Ethylenglykol, Hexamethylentetramin und Gemischen davon.
EP88905072A 1987-05-14 1988-05-04 Verfahren zur stickstoffoxydminderung und zur minimierung der herstellung sonstiger schadstoffe Expired - Lifetime EP0313648B1 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US07/050,198 US4780289A (en) 1987-05-14 1987-05-14 Process for nitrogen oxides reduction and minimization of the production of other pollutants
PCT/US1988/001500 WO1988008824A1 (en) 1987-05-14 1988-05-04 Process for nitrogen oxides reduction and minimization of the production of other pollutants
US50198 1998-03-30

Publications (3)

Publication Number Publication Date
EP0313648A1 EP0313648A1 (de) 1989-05-03
EP0313648A4 EP0313648A4 (de) 1989-12-12
EP0313648B1 true EP0313648B1 (de) 1995-01-11

Family

ID=21963912

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88905072A Expired - Lifetime EP0313648B1 (de) 1987-05-14 1988-05-04 Verfahren zur stickstoffoxydminderung und zur minimierung der herstellung sonstiger schadstoffe

Country Status (20)

Country Link
US (1) US4780289A (de)
EP (1) EP0313648B1 (de)
JP (1) JP2817929B2 (de)
CN (1) CN1030193A (de)
AT (1) ATE116950T1 (de)
AU (1) AU594299B2 (de)
CA (1) CA1309230C (de)
DD (1) DD274171A5 (de)
DE (2) DE313648T1 (de)
DK (1) DK731788A (de)
ES (1) ES2006659A6 (de)
FI (1) FI88464C (de)
GR (1) GR880100315A (de)
HU (1) HU205586B (de)
MX (1) MX167771B (de)
NO (1) NO890147L (de)
PL (1) PL272425A1 (de)
PT (1) PT87493B (de)
WO (1) WO1988008824A1 (de)
YU (1) YU92888A (de)

Families Citing this family (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4902488A (en) * 1987-05-14 1990-02-20 Fuel Tech, Inc. Process for nitrogen oxides reduction with minimization of the production of other pollutants
US5017347A (en) * 1987-02-13 1991-05-21 Fuel Tech, Inc. Process for nitrogen oxides reduction and minimization of the production of other pollutants
ATE113868T1 (de) * 1988-02-26 1994-11-15 Fuel Tech Inc Verfahren zur ermässigung der konzentration von schadstoffen in abgasen.
US4908194A (en) * 1988-03-29 1990-03-13 Natec Mines Ltd. Method for baghouse brown plume pollution control
US5616307A (en) * 1988-04-29 1997-04-01 Nalco Fuel Tech Boiler operation with decreased NOx and waste water discharge
US5441713A (en) * 1988-04-29 1995-08-15 Nalco Fuel Tech Hardness suppression in urea solutions
CH675623A5 (de) * 1988-09-27 1990-10-15 Von Roll Ag
US5240689A (en) * 1989-06-19 1993-08-31 Noell, Inc. Process using two-stage boiler injection for reduction of nitrogen
EP0432166A1 (de) * 1989-07-04 1991-06-19 Fuel Tech Europe Limited Lanzartiges injektionsgerät zum einbringen von chemikalien in abgase
US5047219A (en) * 1989-08-18 1991-09-10 Fuel Tech, Inc. Hybrid process for nitrogen oxides reduction
US5262138A (en) * 1989-08-31 1993-11-16 Union Oil Company Of California Process for NOx abatement
US4978514A (en) * 1989-09-12 1990-12-18 Fuel Tech, Inc. Combined catalytic/non-catalytic process for nitrogen oxides reduction
US5139754A (en) * 1989-09-12 1992-08-18 Fuel Tech, Inc. Catalytic/non-catalytic combination process for nitrogen oxides reduction
DE3935402C1 (de) * 1989-10-24 1991-02-21 Martin Gmbh Fuer Umwelt- Und Energietechnik, 8000 Muenchen, De
US4997631A (en) * 1990-03-07 1991-03-05 Fuel Tech, Inc. Process for reducing nitrogen oxides without generating nitrous oxide
US5165903A (en) * 1990-04-16 1992-11-24 Public Service Company Of Colorado Integrated process and apparatus for control of pollutants in coal-fired boilers
US5543123A (en) * 1990-08-01 1996-08-06 Nalco Fuel Tech Low pressure formation of a urea hydrolysate for nitrogen oxides reduction
US5240688A (en) * 1990-08-01 1993-08-31 Fuel Tech Gmbh Process for the in-line hydrolysis of urea
US5229090A (en) * 1991-07-03 1993-07-20 Nalco Fuel Tech Process for nitrogen oxides reduction to lowest achievable level
US5489419A (en) * 1992-10-13 1996-02-06 Nalco Fuel Tech Process for pollution control
US5536482A (en) * 1992-10-13 1996-07-16 Nalco Fuel Tech Process for pollution control
CA2161135A1 (en) * 1993-05-07 1994-11-24 Joseph R. Comparato Process and apparatus for enhancing distribution of nox -reducing chemicals in a high-solids environment
US5404841A (en) * 1993-08-30 1995-04-11 Valentine; James M. Reduction of nitrogen oxides emissions from diesel engines
US5489420A (en) * 1994-03-10 1996-02-06 Nalco Fuel Tech Nitrogen oxides reducing agent and a phosphate
US5462718A (en) * 1994-06-13 1995-10-31 Foster Wheeler Energy Corporation System for decreasing NOx emissions from a fluidized bed reactor
US5985222A (en) * 1996-11-01 1999-11-16 Noxtech, Inc. Apparatus and method for reducing NOx from exhaust gases produced by industrial processes
US6048510A (en) * 1997-09-30 2000-04-11 Coal Tech Corporation Method for reducing nitrogen oxides in combustion effluents
EP1140327A4 (de) * 1998-11-23 2001-10-10 Mobil Oil Corp Flüssiger harnstoffzusatz zur abgasbehandlung
ATE336472T1 (de) * 2000-03-08 2006-09-15 Isg Resources Inc Kontrolle der ammoniakemissionen von mit ammoniak beladener flugasche in beton
US6280695B1 (en) 2000-07-10 2001-08-28 Ge Energy & Environmental Research Corp. Method of reducing NOx in a combustion flue gas
US20020199156A1 (en) * 2001-05-23 2002-12-26 Fuel Tech, Inc. Hardware-adaptable data visualization tool for use in complex data analysis and engineering design
US6797035B2 (en) * 2002-08-30 2004-09-28 Ada Environmental Solutions, Llc Oxidizing additives for control of particulate emissions
US8449288B2 (en) * 2003-03-19 2013-05-28 Nalco Mobotec, Inc. Urea-based mixing process for increasing combustion efficiency and reduction of nitrogen oxides (NOx)
US7670569B2 (en) * 2003-06-13 2010-03-02 Mobotec Usa, Inc. Combustion furnace humidification devices, systems & methods
US8251694B2 (en) * 2004-02-14 2012-08-28 Nalco Mobotec, Inc. Method for in-furnace reduction flue gas acidity
US7537743B2 (en) * 2004-02-14 2009-05-26 Mobotec Usa, Inc. Method for in-furnace regulation of SO3 in catalytic NOx reducing systems
US7410356B2 (en) 2005-11-17 2008-08-12 Mobotec Usa, Inc. Circulating fluidized bed boiler having improved reactant utilization
US8069824B2 (en) * 2008-06-19 2011-12-06 Nalco Mobotec, Inc. Circulating fluidized bed boiler and method of operation
US10006633B2 (en) 2014-06-03 2018-06-26 Peerless Mfg. Co Infinitely variable injector for improved SNCR performance
CN108619907A (zh) * 2018-04-28 2018-10-09 南京工业大学 一种车用尿素还原剂溶液

Family Cites Families (36)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3846981A (en) * 1970-10-19 1974-11-12 Nanaimo Enviro Syst Corp Emission control process and system
US3801696A (en) * 1971-11-18 1974-04-02 J Mark Apparatus for removing nitrogen oxides from engine exhaust
US3900554A (en) * 1973-03-16 1975-08-19 Exxon Research Engineering Co Method for the reduction of the concentration of no in combustion effluents using ammonia
JPS5333975B2 (de) * 1973-03-28 1978-09-18
JPS5067609A (de) * 1973-10-17 1975-06-06
JPS511138A (de) * 1974-06-24 1976-01-07 Nippon Telegraph & Telephone
JPS514588A (ja) * 1974-07-01 1976-01-14 Hitachi Ltd Dohakanjitsusohoho
JPS5112330A (ja) * 1974-07-22 1976-01-30 Nippon Steel Corp Nabekeidosochi
JPS5176166A (ja) * 1974-12-27 1976-07-01 Mitsubishi Chem Ind Chitsusosankabutsuobunkaisuruhoho
JPS5539971B2 (de) * 1975-02-04 1980-10-15
JPS51143570A (en) * 1975-06-06 1976-12-09 Asahi Chem Ind Co Ltd A method for reduction of nitrogen oxides in exhaust gas
JPS526368A (en) * 1975-07-05 1977-01-18 Hitachi Ltd Process for reducing nitrogen oxides in exhaust combustion gases
JPS5285056A (en) * 1976-01-08 1977-07-15 Toray Ind Inc Removal of nitrogen oxides
JPS5288259A (en) * 1976-01-20 1977-07-23 Toray Ind Inc Removal of nitrogen oxides
JPS5291776A (en) * 1976-01-30 1977-08-02 Mitsubishi Heavy Ind Ltd Treatment of nitrogen oxides in exhaust gas
JPS5295573A (en) * 1976-02-09 1977-08-11 Mitsui Toatsu Chem Inc Decreasing method of nitrogen oxide in exhaust gas
US4208386A (en) * 1976-03-03 1980-06-17 Electric Power Research Institute, Inc. Urea reduction of NOx in combustion effluents
CA1097487A (en) * 1976-04-20 1981-03-17 David W. Turner Method and apparatus for reducing no.sub.x emission to the atmosphere
JPS5314664A (en) * 1976-07-27 1978-02-09 Nippon Steel Corp Method for removing nitrogen oxides contained
JPS5333975A (en) * 1976-09-09 1978-03-30 Hitachi Zosen Corp Lowering method for concentration of nitrogen monoxide in exhaust gas
JPS5379762A (en) * 1976-12-24 1978-07-14 Mitsubishi Heavy Ind Ltd Treating method for nitrogen contained in exhaust gas
JPS5394258A (en) * 1977-01-31 1978-08-18 Kurabo Ind Ltd Control method and apparatus for nitrogen oxides removing apparatus
JPS53128023A (en) * 1977-04-15 1978-11-08 Toray Ind Inc Method for reducing the concentration of nitrogen oxide in combustion effluent gas
JPS53130274A (en) * 1977-04-21 1978-11-14 Toray Ind Inc Treating method for exhaust gas containing nitrogen monoxide
US4325924A (en) * 1977-10-25 1982-04-20 Electric Power Research Institute, Inc. Urea reduction of NOx in fuel rich combustion effluents
JPS5499771A (en) * 1978-01-24 1979-08-06 Mitsubishi Heavy Ind Ltd Controlling method for ammonia injection at dry process exhaust gas dieitration method
JPS54123573A (en) * 1978-03-17 1979-09-25 Matsushita Electric Ind Co Ltd Exhaust gas treating agent
US4473537A (en) * 1982-12-27 1984-09-25 General Electric Company Ammonia control system for NOx emission control for gas turbine exhaust
US4473536A (en) * 1982-12-27 1984-09-25 General Electric Company Catalytic pollution control system for gas turbine exhaust
DE3337793A1 (de) * 1983-10-18 1985-05-02 L. & C. Steinmüller GmbH, 5270 Gummersbach Verfahren zur regelung der zugabemenge an reduktionsmittel bei der katalytischen reduktion von in rauchgasen enthaltenem no(pfeil abwaerts)x(pfeil abwaerts)
US4507269A (en) * 1983-11-10 1985-03-26 Exxon Research & Engineering Co. Non-catalytic method for reducing the concentration of NO in combustion effluents by injection of ammonia at temperatures greater than about 1300 degree K
US4624840A (en) * 1983-11-10 1986-11-25 Exxon Research & Engineering Company Non-catalytic method for reducing the concentration of NO in combustion effluents by injection of ammonia at temperatures greater than about 1300° K.
US4521388A (en) * 1984-03-27 1985-06-04 Shell California Production Inc. NOx reduction in flue gas
GB8622593D0 (en) * 1986-09-19 1986-10-22 Stordy Combustion Eng Ltd Carrying out combustion process
DE3677985D1 (de) * 1986-10-07 1991-04-11 Nippon Kokan Kk Methode und einrichtung zur regelung der denitration von abgasen.
JPH07100131A (ja) * 1993-10-12 1995-04-18 Hitachi Medical Corp 医療用装置

Also Published As

Publication number Publication date
PT87493A (pt) 1989-05-31
HUT56526A (en) 1991-09-30
DK731788A (da) 1989-01-05
EP0313648A4 (de) 1989-12-12
CA1309230C (en) 1992-10-27
DE3852747D1 (de) 1995-02-23
YU92888A (en) 1990-04-30
CN1030193A (zh) 1989-01-11
ES2006659A6 (es) 1989-05-01
WO1988008824A1 (en) 1988-11-17
EP0313648A1 (de) 1989-05-03
MX167771B (es) 1993-04-12
US4780289A (en) 1988-10-25
JP2817929B2 (ja) 1998-10-30
DD274171A5 (de) 1989-12-13
PT87493B (pt) 1992-09-30
AU1807488A (en) 1988-12-06
DK731788D0 (da) 1988-12-30
FI890165A (fi) 1989-01-13
GR880100315A (el) 1989-02-23
PL272425A1 (en) 1989-03-06
HU205586B (en) 1992-05-28
JPH01503372A (ja) 1989-11-16
DE3852747T2 (de) 1995-05-18
FI88464B (fi) 1993-02-15
ATE116950T1 (de) 1995-01-15
FI890165A0 (fi) 1989-01-13
FI88464C (fi) 1993-05-25
NO890147L (no) 1989-01-13
NO890147D0 (no) 1989-01-12
DE313648T1 (de) 1989-08-03
AU594299B2 (en) 1990-03-01

Similar Documents

Publication Publication Date Title
EP0313648B1 (de) Verfahren zur stickstoffoxydminderung und zur minimierung der herstellung sonstiger schadstoffe
US5017347A (en) Process for nitrogen oxides reduction and minimization of the production of other pollutants
EP0306515B1 (de) Mehrstufenverfahren zur verminderung der konzentration von schadstoffen in abgasen
CA1324876C (en) Process for nitrogen oxides reduction and minimization of the production of other pollutants
EP0301085B1 (de) Verfahren zur verminderung von stickstoffoxiden in abgasen
EP0564550B1 (de) Verfahren und vorrichtung zur thermischen zersetzung von distickstoffoxid
AU638196B2 (en) Process for reducing nitrogen oxides without generating nitrous oxide
EP0304480B1 (de) Verfahren zur reduktion von stickstoffoxiden in abgasen mittels zucker
EP0333836B1 (de) Verfahren zur reduktion von stickoxiden und minimierung der produktiven von anderen verunreinigungen
US4877590A (en) Process for nitrogen oxides reduction with minimization of the production of other pollutants
EP0370077B1 (de) Auswaschen von ammoniak
WO1990000440A1 (en) Method for the reduction of sulfur trioxide in an effluent
EP0304478B1 (de) Verfahren zur reduktion von stickoxiden mit minimiertem anfall anderer schadstoffe

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19881229

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

DET De: translation of patent claims
A4 Supplementary search report drawn up and despatched

Effective date: 19891212

17Q First examination report despatched

Effective date: 19900713

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

REF Corresponds to:

Ref document number: 116950

Country of ref document: AT

Date of ref document: 19950115

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3852747

Country of ref document: DE

Date of ref document: 19950223

ITF It: translation for a ep patent filed

Owner name: BARZANO' E ZANARDO MILANO S.P.A.

ET Fr: translation filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19950426

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19950504

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19950531

Ref country code: LI

Effective date: 19950531

Ref country code: BE

Effective date: 19950531

Ref country code: CH

Effective date: 19950531

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

BERE Be: lapsed

Owner name: FUEL TECH INC.

Effective date: 19950531

26 Opposition filed

Opponent name: NOELL-KRC UMWELTTECHNIK GMBH

Effective date: 19951006

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

PLBO Opposition rejected

Free format text: ORIGINAL CODE: EPIDOS REJO

APAC Appeal dossier modified

Free format text: ORIGINAL CODE: EPIDOS NOAPO

APAE Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOS REFNO

APAC Appeal dossier modified

Free format text: ORIGINAL CODE: EPIDOS NOAPO

APAE Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOS REFNO

APAC Appeal dossier modified

Free format text: ORIGINAL CODE: EPIDOS NOAPO

PLBN Opposition rejected

Free format text: ORIGINAL CODE: 0009273

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: OPPOSITION REJECTED

27O Opposition rejected

Effective date: 19980221

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050504

APAH Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOSCREFNO

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20070529

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20070702

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20070525

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20070517

Year of fee payment: 20

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20080503

EUG Se: european patent has lapsed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20080503

PLAB Opposition data, opponent's data or that of the opponent's representative modified

Free format text: ORIGINAL CODE: 0009299OPPO

R26 Opposition filed (corrected)

Opponent name: NOELL-KRC UMWELTTECHNIK GMBH

Effective date: 19951006